Problem: When Will was 5 years old, his allowance was 25 cents. When he was 6, his allowance was 50 cents. When he was 7, his allowance was $1.00. If Will's allowance continued to double each year, what was his allowance at age 11?
Solution: When Will was 7, his allowance was $1.00. It must double 4 more times by the time he is 11 years old. So, his allowance at age 11 was $1\cdot 2^{4}=\boxed{\$16}$ dollars.